cardiac abnormalities (cardiovascular malformation (CVM), hypertrophic cardiomyopathy, tachycardia), predisposition to malignancy, developmental delays, and mental retardation
[ncbi.nlm.nih.gov]
Costello syndrome is a rare congenital disorder typically characterized by severe failure-to-thrive, cardiac abnormalities including tachyarrhythmia and hypertrophic cardiomyopathy
[ncbi.nlm.nih.gov]
abnormalities or cancer predisposition.
[ncbi.nlm.nih.gov]